Party Joining & Friend Server Visibility

1. Allow party leaders to join friends directly from their friends list without having to leave their current party.

2. Show which server friends are currently playing on. I may have several friends online, but I can't tell whether they're all playing together on the same server or spread across different servers. Even a server name, server ID, or an indicator showing which friends are grouped together would make it much easier to find and join friends.

These changes would make it much easier for groups of friends to connect, coordinate, and play together.